Mechanics

CEL ON O2 SENSOR BAD BANK 2

2003 Ford Escape • 142,000 miles

Received code 1130 from mechanic. Came up catalytic exhaust performing below threshold. Saying bank 2 sensor bad. Where is this and does this mean a catalytic converter is bad or just the sensor?
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Bingoprincess
February 22, 2012.




Fault codes never say a part is bad or needs to be replaced. They only indicate the circuit or system that needs further diagnosis. While it's true you will find the sensor in question to be defective about 50 percent of the time, there are a lot of other possible causes for codes to set.

Bank two is on the passenger side. Most systems have an upstream, (closest to the engine), and a downstream, (behind the catalytic converter) oxygen sensor on each bank. The downstream one is just for monitoring the efficiency of the converter.

The code description I have is more informative.

P1130 Lack Of HO2S-11, Fuel Trim At Limit.

It suggests the Engine Computer is trying to correct the fuel / air mixture and doesn't have enough adjustment capability to reach the correct ratio. That suggests the oxygen sensor is not defective; it's just reporting what it sees.

Caradiodoc
Feb 22, 2012.


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